Custom Orthopaedic Implant Design for Stress Shielding

Solution Overview

Problem

Current orthopaedic implants face challenges such as stress shielding due to material and structural discrepancies with native bone, leading to decreased bone density and potential for further injury or re-injury, and issues like adjacent segment degeneration in spine fusions due to off-the-shelf implants not accounting for individual patient bone properties.

Innovation Solution

An implant customization platform that uses patient-specific bone structure and profile information to design and form custom orthopaedic implants with optimal stiffness, strength, and stress distribution, utilizing materials like composite materials to match bone properties and reduce stress concentrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If off-the-shelf orthopaedic implants are used, then manufacturing cost and availability are improved, but stress shielding and bone density loss occur due to material and structural discrepancies with native bone

Engineering Contradiction:

Improvemanufacturing availabilityVSAvoidstress shielding

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The implant design incorporates locally varied material properties and structural characteristics that match the specific bone region being treated. The customization platform analyzes patient-specific bone properties and generates implant designs with tailored stiffness, porosity, and geometry to match local bone characteristics, thereby eliminating stress shielding while maintaining manufacturing feasibility through automated design generation.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system changes multiple design parameters simultaneously including material composition, density, porosity, and geometric dimensions to match patient-specific bone properties. The customization platform adjusts these parameters based on bone density, geometry, and mechanical properties derived from medical imaging, creating an optimal match that prevents stress shielding while maintaining manufacturability.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If custom orthopaedic implants are designed for each patient, then stress distribution and bone health are improved, but device complexity and manufacturing time increase

Engineering Contradiction:

Improvebone health outcomeVSAvoidcustomization complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The customization platform automatically performs the entire design process without requiring manual intervention from engineers. The system self-determines implant geometry, material properties, and structural characteristics by analyzing patient bone data and applying optimization algorithms, thereby reducing device complexity from the user perspective while maintaining high customization benefits for bone health.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The system performs preliminary design and optimization calculations before manufacturing, using patient-specific bone data to pre-determine the optimal implant configuration. This preliminary action includes analyzing bone properties, selecting appropriate materials, and optimizing geometric parameters, which streamlines the subsequent manufacturing process and reduces overall complexity.

Inventive Principle:

Principle #10Preliminary action

3Ease of manufacture

If standard implants are used, then manufacturing simplicity is maintained, but adjacent segment degeneration occurs due to not accounting for individual patient bone properties

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidadjacent segment degeneration

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The implant design incorporates locally varied material properties and structural characteristics that match the specific bone region being treated. The customization platform analyzes patient-specific bone properties and generates implant designs with tailored stiffness, porosity, and geometry to match local bone characteristics, thereby eliminating stress shielding while maintaining manufacturing feasibility through automated design generation.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system changes multiple design parameters simultaneously including material composition, density, porosity, and geometric dimensions to match patient-specific bone properties. The customization platform adjusts these parameters based on bone density, geometry, and mechanical properties derived from medical imaging, creating an optimal match that prevents stress shielding and adjacent segment degeneration.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20220310243A1Customization of an orthopaedic implant

Publication Date: 2022.09.29 JOHNS HOPKINS UNIVERSITY

AI summary

An implant customization platform may receive image data associated with a bone of a patient. The implant customization platform may convert the image data to a structural representation of the bone. The implant customization platform may identify, based on the structural representation, a placement for an orthopaedic implant relative to the bone. The implant customization platform may determine a performance characteristic for a combination of the bone and the orthopaedic implant. The implant customization platform may determine, using an implant customization model, a data representation of the orthopaedic implant based on the structural representation, the placement, and the performance characteristic. The implant customization platform may perform an action associated with the data representation to permit the orthopaedic implant to be formed.